Safety device



Aug. 7, 1951 Filed June 27, 1946 DE LOY J. WHITE ET AL SAFETY DEVICE 4 Sheets-Sheet l IN I 'ENTORS DELOY J. WHITE By JAMES WILSON SMITH Aug. 7, 1951 Filed June 27, 1946 4 Sheets-Sheet 2 v .2- Eb I0 I m 33 5 30 INVENTOR. DELOY J. WHITE By JAMES WILSON SMITH 32 Agent Aug. 7, 1951 DE LOY J. WHITE ET AL 2,563,296 I SAFETY DEVICE Filed June 27, 1946 4 Sheets-Sheet 5 INVENTOR. DELOY J. WHITE By JA ON 8mm MES WILS Age DE LOY J. WHITE ETAL. 2,563,296

Aug. 7, 11951 SAFETY DEVICE 4 Sheets-Sheet 4 Filed June 27, 1946 INVENTOR. DELOY J. WHITE JAMES WILSON SMITH Agent Patented Aug. 7, 1951 UNI-TED STATES PAT ENT OFFICE;

SAFETY DEVICE De Loy .LWhitje, Nbrtli Hollywood, and'JamefsW. Smith Burhank. Calif assigriors to Lockheed Aircraft-Corporation, Burbank; Calif;

A p ies-timin s}, 1946,. Serial No-..,686,660

This invention. relates. to newer operated tools,

and relatesmoreparticularly to safetydevices fen use. with riveters,,squeezerapunches, presses,.andother power. actuated tools. of'this class. Ageneral. object of this invention is to. provide-a.prac-v tical, inexpensive and dependable safety means,

donot obviate; thehazardand-.Sfl' Qusly. interiere.

with. the positioning of the work pieces.

It is .an object-of thapresent; invention to. provide a safety means, for. use. on squeezing press ing, punching; and. riveting;.,machines which pre-.

eludes. the possibility of. injury to theop.

erator. in the; event. the machineis put.into op: eration when; his. hand or other part of. his bodyis; between the activeework partsofj the machine. Thesafety deviceis such that,the ac.-

tive force. or power ofIthe. machinefis: notapplied to the. part of, the. operators body thate is unintentionallyon accidentally caughabetweenthe squeezing-, pressing. punching or riveting; elements.

Anotherobject. of;v theinvention is. to provide asafety device :.othis ;.character that thorough.- ly dependable and. does. not. require the use of electric. circuits-, fluid pressure devices orv other instrumentalities-liable. to, become inoperative.

Another. object of. the. invention. to provide a.. saf,ety devicethatdoes not-interfere;withjtiie normal operationrof; the. machine or require any change, in the. manual; handling of 1" the, work? or inthe control ofthemachine.

It. is, anothen, object of the. invention.v to. pro?- vide. a. safety device. that. is... installed'ldireefli." n oneof .theactiveworkparts, of themachinejand that doesnotnecessitatealteration,ofitheprimary machine. elements A further objectjofj the invention'isg'toprovide a. simple, inexpensive safety' device: that. may be. easily instal1ed',ei-ther as: an appliance forj'a previously assemblediimachinef or" as: arrv original machine. part.

Other objects and fe'aturesjoffthe invention will be readily, understoodv from; thefollowing detailfi description'of typicalpreferredi forms of th'e'infvention wherem reference. willf bej made t'o' the accompanyingtdrawing fin whichz ofthe-safety device in the partially operatedpo'si' t'ion ready to apply the active force to the. work piece;v

Figure 3 is a view similar to Figure 2showing the parts in a released condition" where they ac.- ti-veforce cannot be transmitted to an object between-the active machine elements;

Figure ,4 is. a fragmentary verticali sectional view with certain parts. appearing in sideeleva'w tion, showing. a rivet beingdriven;

Figure 5 is a transverse detailedsectional' view taken: substantially as indicated by. line 5-5.on Figure 4;

Figure 6' is atransverse sectional View" of an.- other form ofthe invention, .beinga view taken as indicated by line 6 6 on Figure T;

Figure? is. a vertical'sectiohalview of 'saidio'tliier form of the invention with certain parts apipearing. in side elevation; and;

Figure 8 is afragmentary verticallse'ctional View of a modification of the device shown in Figure T.

In- Figure ,1 we have shown. a' pneumatically operatedriveter or squeezer for. driving rivets and have illustrated. one form of 'theiiive'ntion associated with the machine; It. is to be under stoodthat this is merely a typicalapplic'atio'n andthe invention is not primarily"concernedwith the detailsofth'e machine. For thi's"reason,,the machine is shown in amore or" less diagrammatic manner. The riveting 'm'ach'ine' comprises- 'a', base or frame. Ill carrying a stationary a'n'v'il- I1: The anvil I I' may be capable of vertical adjustment so. as, to. vary the position" of the" active pfortion ofj'thej work stroke; The" upper" portion of" the baseis. substantially c -shaped to receive the work pieces; and theupper' arm" of the C" carries a" cyliri'd'er" and piston mechanism I2: A valve I 3," the details of" which" are'not required. for a full understanding of the "invention; controls the delivery and releaseof actuating-"fluid pressure to and from the opposite ends of" the cylinder mechanism I2; The valve I3 is controlled by a" foot' pedal I4, the-pedal being connected with the; valve" by a flexible cable I 5 and a bell crank I 6. The piston rod I "'I"of thecylindrmechanism I 2 carries a block lfl which is supported and guid ed. by a'- tra;ck-* I9"; A- ca-m lever 2 F is l pivoted in the-framed fl -and the block I8' carries -a' rollr'2ll for swinging? the lever downwardly as the piston rod llmoves-forwardly; The-'=upper arm orthe frame has a vertical bushing 22 for slidably guiding an element of the set or die holder hereinafter termed the body 23 of the safety device. The upper end of this body 23 is engaged by the lever 2| to be forced downwardly upon actuation of the cylinder mechanism l2. Spring means 8 serves to return the lever 2| and body 23 after each actuation.

The safety device illustrated in Figures 1 to v inclusive, comprises the body 23, a set or diecarrying member 24 related to the body for relative longitudinal movement, and means 25 for coupling the body and member for the transmission of force therebetween, which means is released or ineifective in the event movement of the member 24 is prematurely resisted. While we have shown the safety means associated with the movable work-engaging part, it is to be understood it is adapted for other installations.

The body 23 is an elongate part slidable in the above described bushing 22. A reduced stem 26 in the upper end of the body is engaged by the cam lever 2| and has an opening 21 for receiving the return spring 8. The vertical movement of the body 23 is limited by a pin 28 projecting through the wall of the bushing 22 and operating in an axial groove 29 in the body. A central vertical opening 30 enters the body 23 from its lower end to receive the member 24 and this opening is of considerable length. The body 23 is proportioned so that its lower end is at or adjacent the lower face 3| of the upper frame arm when the cam lever 2| is fully actuated. This position of the body is shown in Figure 4.

The member 24 for carrying the rivet die or set is an elongate cylindrical part slidably received in the opening 30 of the body 23. The member extends downwardly beyond the lower end of the body 23, and is provided at its lower extremity with a replaceable rivet set 32, or the equivalent. If desired, the upper portion of the member 24 may be tubular. A transverse pin 33 is carried by the member 24 and operates in a vertical slot 34 in the body 33 to limit the downward travel of the member relative to the body, and a set screw 9 limits the upward travel of the member. A light coiled spring 35 is engaged between the upper end of the member 24 and the upper wall of the opening 30 to cushion the upward movement of the member when a new set 32 is being installed. The member 24 and its set 32 are vertically aligned with the anvil The means 25 is an important feature of the invention serving under normal operating conditions to positively transmit downward movement from the body 23 to the member 24, but disconnecting or freeing the member from the body in the event some object such as the operators hand or finger, prematurely arrests downward travel of the member. In the form of the invention illustrated in Figures 1 to 5 inclusive, the means 25 comprises an annular series of steel balls 31 surrounding the member 24 and an annular groove 38 in the member for partially receiving the balls. The upper and lower walls of the groove 38 are flared or outwardly divergent, and the groove and balls are proportioned and related in such a way that the groove is capable of receiving only about one-half of each ball as shown in Figure 2.

The means 25 further includes a conical or downwardly and outwardly sloping face 39 on the lower end of the body, and a retainer 40 associated with the frame ill to project inwardly at annular and provided to engage downwardly against the series of balls 31. The retainer 40 may be an annular or ring-like part arranged in spaced surrounding relation to the projecting portion of the member 24. Means are provided to guide the retainer 40 for limited vertical movement and to yieldingly resist downward travel of the retainer. Screws 4| are threaded in openings in the frame It) and have their heads spaced below the face 3|. Unthreaded portions of the screws 4| slidably pass through openings 42 in the retainer 40 to guide the retainer for vertical travel, and springs 43' are arranged under compression'between the heads of the screws and the retainer. The springs normally hold the retainer upwardly against the face 3| and are compressible to allow the retainer to move downwardly to a position such as shown in Figure 4. When the springs 43 are in the compressed condition, their convolutions may engage one with the other to positively limit downward travel of the retainer. The parts are related and proportioned so that the balls 31 cannot become displaced from the assembly when the retainer 40 is in its lowermost position, the retainer and the member 24 serving to prevent such displacement.

In the'operation of the device illustrated in Figures 1 to 5 inclusive, the spring 8 normally holds the body 23 in a raised position where its lower face 39 is some distance above the retainer 40 and the member 24 is also raised to occupy a position where its groove 38 is spaced above the retainer. The balls 31 rest on the retainer and are confined to the annular space between the interior of the bushing 22 and the external surface of the member 24. Thus prior to and at the beginning of the work-cycle the parts in the positions just described, the lower face 39 of the body 23 being spaced a considerable distance above the retainer 4|], the member 24 being raised so that the groove 38 is spaced above the retainer and the balls 31 being at rest on the retainer 4|] where they are confined between the wall of the bushing 22 and the periphery of the member 24. Upon depressing the pedal H, the valve I3 is reversed to operate the cylinder and piston mechanism l2, which in turn actuates the cam lever 2| to move the body 23 downwardly. During such downward movement of the body, the member 24 travels downwardly by gravity and when its groove 38 reaches a position such as shown in Figure 2, the balls 31 move into the groove. The pitched face 39 of the body 23 assists in moving the balls into the groove. The balls 31 are only partially received by the groove, and the face 39 remains in engagement with the balls. Thus the balls 31 are engaged between the face 39 and the wallsof the groove 38, and serve to positively transmit downward movement from the body 23 to the member24. Figure 2 illustrates the balls 31 in the force-transmitting position. As the body 23 continues downwardly, the member 24 is positively moved with the body and the retainer 40 likewise moves downwardly with the body, the balls being held between the face 39 and the walls of the groove 38 by the retainer. In practice, the actual working stroke of the member 24 occurs during the downward travel of the retainer 40. Figure 4 illustrates the parts in the fully actuated positions where the set 32 has driven or upsetjtherivet R. against the anvil Upon the return ,of the pedal I4 to its raised position, the cylinder mechanism |2 1 restores the block I 8 and the spring 8 'returns the body 23 to itsraised position. Thepin 33 and a rod 48.

r oveop rat t s r the em erli to the raised position,

mtneevm' that the operators arm or hand;-

isunderthe. set 32 when thepedal i4 is depressed, the body 23 is positively moved downwardly as above described. Theballs 31 simply rest on the retainer at this time. The downward travelof groove 38 from assuming a position adjacent the retainer 40, the groove remaining in a position suclias illustrated in Figure 3. Accordingly, the end face 39 of thebody 23 moves downwardly past the groove 33 and ultimately engages. the. balls 31. However, at this time the balls 31 are,

confined between the wall of the bushing. 22 and.

the plain surface of the member 24, and no down- Ward; force istransmitted from the balls to the;

member. The balls 37 are free to roll down;

wardly on the member 24 during the remainder of the stroke. Thus the power stroke of the body 231s completed without the transmission of downward force to the member 24, and the only'pressure applied to the workmans hand or. fingerresults from the weight of the member 24. and the action of the light spring 35. This is insufiicient to injure the operator. It will be observed that the safety device does not in any way interfere with the normal operation of the machine, but prevents injury to the operator if he depresses the pedal it at a time when his hand or arm is above the anvil H.

The form of the invention illustrated in Fig ures'6 and 7' includes a body operated by the cylinder mechanism 12, a set-carrying member 46 movable. longitudinally relative to the body, and means 41 for transmitting movement from thebody to the member, which means is rendered ineffective in the event that downward travel of the member 481s. prematurely resisted.

Inthis form of the invention. the body 45 is a tubular part, screw-threaded to the lower end ,of

lever 2| and is returned by the spring 8 in the same manner as the body 23 described above. The body 45 is, slidable in the bushing 22 and freelyenters acage 49 attached to the frame. it). Iprefer toadjustably secure the cage 49 so that it may be shifted or adjusted vertically. In the structure. illustrated, the cage 49 is adjustably screw-threaded into a, nut. welded on the above described face 3|.

Themfimber 4661s anelongate stem-like part, and its upper portion is freely received in the body 45. The lower portion of the member 46 is reduced in diameter, and a suitable rivet set S, or the equivalent, is secured to its lower end. The reduced portion of the member 46 is slidably guided in an opening 5| in the lower wall of the cage 49.

The means 41 is an important feature of the invention and comprises a set of tongues or 4 fingers 53 on the body 45 for cooperating with The rod 48 is operated by the cam ane . f i'q' ba a e n re es s. Thecage49. is providedwithan annular in't'e a l. cam'surfa'ce 64 which curves or slopes. ddv'v'nwardly and inwardly with respect to. the. longitudinal axis of the. assembly. The balls 54., ride along the internal. surface of the cage 49.:

and are adapted. to cooperate with thecam surfaee 64 to cause; inward flexing of the fingers Theselzecarrying member 46 is provided with; one or. more, shoulders for engaging with mat ingparts on the. body 45. In the. construction substantially the same inclination. The parts are related so that the surfaces, 55. and 55,.wi1l,

clearor pass one another when thefingers 53 are in vtheirnormal or unflexed positions shown in;

Figure 7. However, when the fingers 53are flexed inwardlyby the camsurface 5 4, the surfaces 55.

are brought into firm cooperation with the sur faces 55 for the transmission of downward move-. ment from the body 45 to the member lfi. A flange. or lip 5'l,is,formed on the upper end of the member 45 and is engageable witha seat 58. in the upper surface 56 to limit the downward travel of themember relative to the body 45, and to prevent displacement of themember from the: assembly. A light coiled spring 59 may be engaged against the upper end of the, member 46 to cushion relative movement between the body and member.

Figure 8 illustrates a slight modification of the device of Figures 6. and 7. In thisconstruction thefinger's Bllare separately formed parts secured to the body 45 by horizontal hinge pins 5|. Springs 62 are associated with the fingers Bil-to normally urge them outwardly so that the balls 54remain in engagement with the internal surface of the cage 49. The surfaces 55-are formed on the inner sides of the fingers Ell-for cooperation with the surfaces 55. All other parts of the device may be the same as described above, and

the arrangement of Figure 8 operates in the same manner as the device of Figures-6 and 7.

In the operation of the safety device shown in Figures Grand 7, the pedal 14 is depressed to actuate the mechanism l2, which in turn moves the body 45 downwardly toward the anvil ll. During this downward movement of the body 45 gravity causes the member 45 to move downwardly with the body. Thus the surfaces 55 remain in opposed and aligned relation to the surfaces 56 substantially as shown in Figure 7. When the body 45 approaches the lower end of its stroke, the balls 54 engage the cam face 64 and the fingers 53 are flexed inwardly. This brings the surfaces 56 into cooperation with the surfaces 55. The cam surface 64 is designed to move the fingers 53 inwardly an extent just sufficient to bring the surfaces 56 into engagement with the surfaces 55. When this has occurred, the balls 54 leave the cam surface 64 and continue downwardly along the cylindrical surfaces of the cage. The pitch or inclination of the engaging'surfaces 55 and 56 assures the positive transmission of downward movement from the body 45 to the e sloping. or. curved projection; I

member 46. Thus the member 46 is positively actuated so that the set S may drive the rivet.

In the event that the operators hand or other object is between the set S and the anvil l I when the pedal I4 is depressed, the body 45 is actuated downwardly as above described. However, the set S moves into engagement with the object or hand and stops this downward travel. Accordingly, the surfaces 56 on the body 45 move downwardly past the stationary surfaces 55 of the member 46 and when the balls 54 co-operate with the cam surface 64 to flex the fingers inwardly, the surfaces 55 and 56 are out of register. The surfaces 56 are below their companion surfaces 55 and cannot engage them. Accordingly, the body ,45 moves downwardly around the member 46 without transmitting movement. The only force applied to the operators hand is the weight of the member 46 and he is saved from injury. The point at which the cam surface 64 actuates the fingers 53 may be adjusted or set by threading the cage 49 in the nut 50, and the cage may be secured or locked in the adjusted position by a nut 10.

Having described only typical forms of the invention, we do not wish to be limited to the specific details herein set forth, but Wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and/ or fall within the scope of the following claims.

We claim:

1. In a machine having a work part movable toward a work piece and power means for actuating the work part, the combination of a body movable toward the work piece by the power means and having a longitudinal opening, a member movable in the opening and extending therefrom, the extending portion of the member carrying said work part, the member being free to move the body when the same is actuated toward the work piece, the member having a groove and the body having a shoulder, the groove and shoulder being in substantially aligned relation so long as the member moves with the body, and balls adapted to engage with said groove and shoulder to transmit movement from the body to the member during a final portion of the movement but being incapable of engaging with the groove for the transmission of movement in the event an object interferes with said free movement of the member.

2. In a machine having a work part movable toward a work piece and power means for actuating the work part, the combination of a body movable toward the work piece by the power means and having a longitudinal opening, a member movable in the opening and extending therefrom, the extending portion of the member carrying said work part, the member being free to move with the body and being adapted to be stopped by an object between said work part and the work piece, the body having an end face, a series of balls, a yieldingly mounted retainer supporting the balls in position to be engaged by said face, and walls on the member defining a groove for partially receiving the balls for the transmission of movement from the body to the member when the groove moves to a position to partially receive balls when the same are supported by said retainer, said groove failing to come into the ball-receiving position in the event an object interferes with said free movement of the member.

3. In a machine having a work part movable toward a workpiece and power means for actuating the work part the combination of; a body movable toward the workpiece by the power means and having a longitudinal opening, a member movable in the opening and extending therefrom, the extending portion of the member carrying said work part, a shoulder on the body facing generally toward the workpiece, a shoulder on the member facing away from the workpiece, an annular series of balls engageable between said shoulders to transmit movement from the body to the member, and means supporting the balls at the shoulder of the body so that the balls engage between the two said shoulders to positively transmit movement from the body to the member in the event movement of the member toward the workpiece, and together with the body, is unresisted prior to the engagement of the work part with the workpiece.

DE LOY J. WHITE. JAMES W. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 999,850 Palmer Aug. 8, 1911 1,308,775 Day July 8, 1919 1,309,246 Smith July 8, 1919 1,684,296 Brodsby Sept. 11, 1928 1,869,895 Hazenfield Aug. 2, 1932 1,945,116 Macfie Jan. 30, 1934 2,259,257 Mac Blane Oct. 14, 1941 2,400,486 Carlyle May 21, 1946 

